Portable seating apparatus are well known and popular being used for sporting events such as football games, soccer games, golf, tennis, and the like. Other uses include sports activities like hunting, fishing, camping, and other similar activities. The primary aspects of a portable seating apparatus are that they are light in weight to be easily transportable and easily expanded into an open state and stowed into a closed or transport state, wherein at the same time having a fairly rigid framework structure when the seating apparatus is in the open state (for seating by the user) for stability and comfort of the user. Although there are numerous configurations for effecting the structural transition from and to the open and closed states known in the prior art for portable seating apparatus, currently the technology and the market seems to favor the scissors style structure that is pivotally connected to the midpoint of the support legs wherein operationally the support legs move inward and outward laterally while the support legs remain substantially parallel during this inward and outward movement. Further, the support legs are fully extended outwardly to form the open state of the portable seating apparatus having typically a flexible panel that conforms to the seat bottom and seat back portion when the support legs are fully extended outwardly. In putting the portable seating apparatus into the closed or stowed state the support legs are moved toward one another while the flexible seat bottom and back panel fold to allow the support legs to come together putting the portable seating apparatus into its stowed state.
Given the above popular scissors type folding structure for portable seating apparatus it is also utilized in the present invention, the focus of the present invention for the portable seating apparatus is upon the interface of the support legs with the surface that is of varying levels of softness. In looking at the prior art in the area of novel support leg interfaces with a surface support enhancement of portable seating apparatus, starting with the older design having a rigid seat bottom frame and back frame that are pivotally connected to one another (having a single plane of movement to collapse the portable chair) that collapse toward being adjacent to one another to be in the closed or stowed state is shown in U.S. Pat. No. 4,915,335 to Miles, wherein disclosed is a lawn chair stabilizer that has detachable tabs removably engaged to the support leg frame structure, wherein the tabs are operational to somewhat increase the surface area contact size and enhance lateral or side to side stability only. However, noting that Miles requires that the support legs be rigid and at least two of the support legs to have a fixed relationship to each other, see FIGS. 9 through 15. Furthermore, Miles does not enhance the portable chair stability if the user individual leans either forward of backward, again see FIGS. 9 through 15. Continuing for a similarly situated portable chair that folds to a closed or stowed state much like Miles, is in U.S. Pat. No. 5,087,095 to McFate wherein disclosed is a recreational chair for use in a beach environment or more specifically for use on a surface of sand. The portable chair in McFate is accompanied by certain attachments that are useful for sunning on a sandy surface, wherein these attachments are also provided for allowing easy transport of the chair upon the back of the user; see the abstract and FIGS. 2 and 3 in particular. A plurality of pockets are included in McFate that include a closable pouch located along the bottom of the chair for storing a length of foldable material or tarp suitable for placing upon a beach sandy surface for the purpose of lying thereon. The tarp in McFate may comprise any suitable material such as lightweight canvas or the like that is easily foldable into the pouch when not in use, with the tarp having a length of approximately six to seven feet being utilized in order to accommodate either a male or female body when lying full length thereon, see column 3, lines 3-13. McFate, also anchors the support legs in a tent pole fashion by driving a tent type stake that flexibly connects to the support leg, while this arrangement provides for preventing the chair from blowing away, it does not protect against the support leg from sinking into the sand surface, see FIG. 4 in particular.
Further in the portable chair apparatus prior art, in what appears to be a combination of Miles and McFate, however, leaning more towards Miles is disclosed in U.S. Pat. No. 5,513,900 to Iglesias that includes a planar chair stabilizing device for rotatable attachment to the ground level, pivotally horizontally attaching to an extending leg member portion of a chair. The device in Iglesias includes a stabilizing base and a gripping member fixed to the base having a slit in the portion of the gripping member not fixed to the base provides access to a central opening sized and shaped to receive the horizontally extending leg member portion, however allowing the chair to have free movement and not resisting forward or backward leaning, being the same drawback as Miles. The gripping member in Iglesias is also sufficiently firm to grip and hold the leg member portion within the central opening and to hold the base parallel to the leg member portion during use of the chair, wherein the base, on installation of the device, extends sufficiently outward to the side of the chair to prevent tipping of the chair to the side during use, see column 1, lines 52-67. The gripping member in Iglesias is sufficiently flexible to permit installation of the device by inserting the leg member portion through the slit into the central opening, see FIG. 5, additionally as in Miles, Iglesias requires a fixed rigid relationship between at least two support legs thus further limiting the folding structure options available to place the chair into the closed or stowed state.
Moving forward in looking at the prior art that is somewhat similar to McFate in function by providing a portable chair holddown as against the wind, in U.S. Pat. No. 6,290,197 to Newton, disclosed is a portable hold down device having weight mass which is connectable to a portable object, such as a portable folding chair, for maintaining the portable chair in a substantially stable condition so that the wind will not move and/or blow the portable chair about, see FIG. 1 for attachment to a current scissors folding type of portable chair with continuously substantially parallel support legs and FIG. 6 for attachment to a rigid frame pivoting seat bottom and rigid frame back folding type portable chair structure. The portable hold down device in Newton includes a portable hold down assembly having a weight sufficient to maintain the portable object in substantially stable condition when the hold down assembly is connected to the portable object, see Column 1, lines 43-52. The first connector assembly in Newton is removably connectable to the portable chair frame whereby when the first connector assembly is connected the portable chair support leg structure, wherein the portable chair is maintained in a substantially stable condition as against wind and the like. A second connector assembly in Newton is supported by at least one of the hold down assemblies and the first connector assembly so as to be extendable outwardly therefrom with the second connector assembly removably connectable to at least a portion of the portable chair having a different orientation than the portion of the portable object to which the first connector assembly is removably connectable, see FIG. 1 as previously described, with the attendant difficulty of attaching the weight. Thus as in McFate, Newton does not prevent the support legs of the portable chair apparatus from sinking into a soft surface, further, even though Miles and Iglesias do provide some increased surface area at the contact of the support leg on the surface, it is not much of an increase in surface area and does not provide for resistance against forward or backward movement of the individual user.
As an example of the previously discussed current scissors type of portable chair apparatus, wherein the support legs remain substantially parallel in going from the open state wherein the individual user can sit in the portable chair to the closed or stowed (transport) state and vice versa, see U.S. Pat. No. 6,505,885 to Tang that basically discloses the structural framework of the scissors mechanism, see in particular FIGS. 1 through 4 in going from the open state to the closed state. Note that in Tang, there are four small in area support leg rests that are adjacent to the surface, thus providing little support for the chair and individual user when the surface is a soft material, however, the focus in Tang is upon the scissors folding mechanism and not the surface contact supports. Also for a similar invention to Tang, see in U.S. Pat. No. 6,637,811 to Zheng, for a simpler version of Tang, Zheng however, using the scissors mechanism in a single axis of movement (laterally) and pivoting the support legs perpendicular to the lateral movement for a simpler design, while accomplishing the same function as Tang, albeit for a smaller portable chair.
What is needed is a portable chair apparatus that is adaptable to being functional upon a soft surface matter material, such as marsh type wet soil, snow, sand, and the like that can allow the individual user to sit comfortably and even potentially lean either backward or forward plus laterally side to side without fear of one chair leg sinking appreciably more than the other chair legs thereby upsetting the user who has to get out of the chair, remove the sunken leg from the surface matter and attempt to move the chair to another location with a harder more stable surface.